Oak Felder builds a deliberately huge, wet hall reverb on a lead vocal, pushing the decay time until it sounds almost too big to use. The idea is to give the reverb its own character and texture instead of keeping it invisible, but that size creates an obvious problem: it clashes with and buries the vocal.
His fix is to sidechain the reverb return through Waves Curves Resolve, keyed off the dry vocal. Whenever the vocal is present, the plugin carves out the specific frequencies and moments in the reverb that fight with it, then lets that same content spring back the instant the vocal drops out.
The result keeps the reverb's sheen and tail fully audible in the gaps while staying out of the way during the phrase itself. It's a practical way to run big, personality-driven reverbs on vocals without sacrificing clarity or intelligibility, using dynamic EQ as a sidechain filter rather than just trimming the reverb down until it's safe.